Pump assembly including fluid cylinder and tapered valve seats

ABSTRACT

According to one aspect, a pump assembly includes a fluid cylinder, the fluid cylinder including a fluid passage, the fluid passage defining a tapered internal shoulder of the fluid cylinder, the tapered internal shoulder defining a first angle. A valve controls flow of fluid through the fluid passage. The valve includes a valve seat, which is disposed in the fluid passage and includes a tapered external shoulder, the tapered external shoulder defining a second angle. In one embodiment, the first tapered external shoulder engages the first tapered internal shoulder to distribute and transfer loading.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S. patentapplication No. 61/594,811, filed Feb. 3, 2012, the entire disclosure ofwhich is incorporated herein by reference.

This application claims the benefit of the filing date of U.S. patentapplication No. 61/683,526, filed Aug. 15, 2012, the entire disclosureof which is incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates in general to pump assemblies and, inparticular, a reciprocating pump assembly including a fluid cylinder andvalve seats.

BACKGROUND OF THE DISCLOSURE

Reciprocating pump assemblies typically include fluid end blocks orfluid cylinders and inlet and outlet valves disposed therein. Duringoperation, the inlet and outlet valves typically experience high loadsand frequencies. In some cases, valve seats of the inlet and outletvalves, as well as portions of the fluid cylinder engaged therewith, maybe subjected to highly concentrated cyclic loads and thus may fatigue tofailure. Moreover, it is sometimes difficult to remove valve seats fromthe fluid cylinder for replacement, which difficulty may result indamage to the fluid cylinder. Further, when replacing a worn valve seator producing a new pump assembly, an incorrect valve seat mayunintentionally be disposed in the fluid cylinder, which may hurt pumpperformance and possibly damage the fluid cylinder or valve seat. Inmany cases, this mix-up of parts is possible because differences betweenvalve seats may not be easily discernable upon visual inspection.Therefore, what is needed is an apparatus or method that addresses oneor more of the foregoing issues, among others.

SUMMARY

In a first aspect, there is provided a pump assembly that includes afluid cylinder having a first axis, the fluid cylinder includes a firstfluid passage through which fluid is adapted to flow along the firstaxis, the first fluid passage defining a first tapered internal shoulderof the fluid cylinder, the first tapered internal shoulder defining afirst angle from the first axis; and a first valve to control flow offluid through the first fluid passage, the first valve includes a firstvalve seat disposed in the first fluid passage, the first valve seathaving a second axis that is aligned with the first axis, the firstvalve seat includes a first tapered external shoulder, the first taperedexternal shoulder defining a second angle from the second axis; whereineach of the first and second angles ranges from about 10 degrees toabout 45 degrees measured from the first axis and the second axisaligned therewith.

In an exemplary embodiment, the first tapered internal shoulder and thefirst tapered external shoulder define first and second frusto-conicalsurfaces, respectively; and wherein the first tapered internal shoulderengages the first tapered external shoulder to distribute and transferloading between the first and second frusto-conical surfaces.

In certain exemplary embodiments, the first and second angles are equal.

In another exemplary embodiment, each of the first and second angles isabout 30 degrees measured from the first axis and the second axisaligned therewith.

In certain exemplary embodiments, the fluid cylinder further includes apressure chamber in fluid communication with the first fluid passage; asecond fluid passage in fluid communication with the pressure chamberand through which fluid is adapted to flow along the first axis, thesecond fluid passage defining a second tapered internal shoulder of thefluid cylinder, the second tapered internal shoulder defining a thirdangle from the first axis; a fluid inlet passage in fluid communicationwith the pressure chamber via the first fluid passage; and a fluidoutlet passage in fluid communication with the pressure chamber via thesecond fluid passage; wherein the pump assembly further includes asecond valve to control flow of the fluid through the second fluidpassage, the second valve includes a second valve seat disposed in thesecond fluid passage, the second valve seat having a third axis that isaligned with each of the first and second axes, the second valve seatincludes a second tapered external shoulder, the second tapered externalshoulder defining a fourth angle from the third axis; and wherein eachof the third and fourth angles ranges from about 10 degrees to about 45degrees measured from the first axis and each of the second and thirdaxes aligned therewith.

In another exemplary embodiment, the second tapered internal shoulderand the second tapered external shoulder defines third and fourthfrusto-conical surfaces, respectively; and wherein the second taperedinternal shoulder engages the second tapered external shoulder todistribute and transfer loading between the third and fourthfrusto-conical surfaces.

In yet another exemplary embodiment, the third and fourth angles areequal.

In an exemplary embodiment, each of the third and fourth angles is about30 degrees measured from the first axis and each of the second and thirdaxes aligned therewith.

In another exemplary embodiment, the first valve seat further includes aseat body, the seat body includes an enlarged-diameter portion at oneend thereof, the enlarged-diameter portion includes the first taperedexternal shoulder and defining a first cylindrical surface extendingaxially from the first frusto-conical surface, the first cylindricalsurface defining a first outside diameter; a bore formed through theseat body, the bore defining a second cylindrical surface, the secondcylindrical surface defining a first inside diameter; wherein the firstfluid passage includes an enlarged-diameter portion and areduced-diameter portion extending axially therefrom; wherein theenlarged-diameter portion of the first fluid passage defines the firsttapered internal shoulder of the fluid cylinder; wherein thereduced-diameter portion of the first fluid passage defines an insidesurface of the fluid cylinder and a second inside diameter; wherein theenlarged-diameter portion of the seat body is disposed in theenlarged-diameter portion of the first fluid passage; wherein the seatbody defines an outside surface that is engaged with the inside surfaceof the fluid cylinder; and wherein the outside surface defines a secondoutside diameter.

In yet another exemplary embodiment, at least one of the inside surfaceof the fluid cylinder and the outside surface of the seat body istapered at a taper angle from the first axis and the second axis alignedtherewith, the taper angle ranging from greater than 0 degrees to about5 degrees measured from the first axis and the second axis alignedtherewith.

In an exemplary embodiment, the first valve seat further includes anannular groove formed in the outside surface of the seat body, theannular groove defining a groove diameter; and a sealing elementdisposed in the annular groove and sealingly engaging the inside surfaceof the fluid cylinder.

In another exemplary embodiment, each of the first and second angles isabout 30 degrees; wherein the first outside diameter is about 5 inches;wherein the first inside diameter is about 3 inches; wherein the secondinside diameter is about 4.5 inches; wherein the groove diameter isabout 4 inches; and wherein the second outside diameter is about 4.5inches.

In yet another exemplary embodiment, the fluid cylinder further includesa pressure chamber in fluid communication with the first fluid passage;and wherein the pump assembly further includes a housing connected tothe fluid cylinder, and a plunger rod assembly extending out of thehousing and into the pressure chamber.

In a second aspect, a fluid cylinder for a pump assembly is provided,the fluid cylinder having a fluid passage axis and includes a firstfluid passage through which fluid is adapted to flow along the fluidpassage axis, the first fluid passage defining a first tapered internalshoulder of the fluid cylinder, the first tapered internal shoulderdefining a first angle from the fluid passage axis, the first angleranging from about 10 degrees to about 45 degrees measured from thefluid passage axis; and a pressure chamber in fluid communication withthe first fluid passage.

In certain exemplary embodiment, the first angle is about 30 degreesmeasured from the fluid passage axis.

In an exemplary embodiment, the fluid cylinder includes a second fluidpassage in fluid communication with the pressure chamber and throughwhich fluid is adapted to flow along the fluid passage axis, the secondfluid passage defining a second tapered internal shoulder of the fluidcylinder, the second tapered internal shoulder defining a second anglefrom the fluid passage axis; and a fluid outlet passage in fluidcommunication with the pressure chamber via the second fluid passage;wherein the second angle ranges from about 10 degrees to about 45degrees measured from the fluid passage axis.

In another exemplary embodiment, the first and second angles are equal.

In yet another exemplary embodiment, each of the first and second anglesis about 30 degrees measured from the fluid passage axis.

In certain exemplary embodiments, the first fluid passage includes anenlarged-diameter portion and a reduced-diameter portion extendingaxially therefrom; wherein the enlarged-diameter portion of the firstfluid passage defines the first tapered internal shoulder of the fluidcylinder; and wherein the reduced-diameter portion of the first fluidpassage defines an inside surface of the fluid cylinder and an insidediameter.

In another exemplary embodiment, the inside surface is tapered at ataper angle from the fluid passage axis, the taper angle ranging fromgreater than 0 degrees to about 5 degrees measured from the fluidpassage axis.

In an exemplary embodiment, each of the first and second angles is about30 degrees; and wherein the inside diameter is about 4.5 inches.

In a third aspect, there is provided a valve seat adapted to be disposedwithin a fluid cylinder for a pump assembly, the valve seat having avalve seat axis and includes a seat body, the seat body includes anenlarged-diameter portion at one end thereof, the enlarged-diameterportion includes a first tapered external shoulder, the first taperedexternal shoulder defining a first angle from the valve seat axis, and afrusto-conical surface extending at the first angle from the valve seataxis, the first angle ranging from about 10 degrees to about 45 degreesmeasured from the valve seat axis, wherein the enlarged-diameter portiondefines a first cylindrical surface extending axially from thefrusto-conical surface, the first cylindrical surface defining a firstoutside diameter, wherein the seat body defines an outside surface, theoutside surface defining a second outside diameter that is less than thefirst outside diameter, and wherein the frusto-conical surface isaxially disposed between the outside surface and the first cylindricalsurface; and a bore formed through the seat body and through which fluidflows along the valve seat axis, the bore defining a second cylindricalsurface, the second cylindrical surface defining an inside diameter thatis less than the second outside diameter.

In an exemplary embodiment, the first angle is about 30 degrees measuredfrom the valve seat axis.

In another exemplary embodiment, the outside surface of the seat body istapered at a second angle from the valve seat axis; and wherein thesecond angle ranges from greater than 0 degrees to about 5 degreesmeasured from the valve seat axis.

In yet another exemplary embodiment, the valve seat includes an annulargroove formed in the outside surface of the seat body, the annulargroove defining a groove diameter that is less than the second outsidediameter and greater than the inside diameter; and a sealing elementdisposed in the annular groove.

In certain exemplary embodiments, the first angle is about 30 degreesmeasured from the valve seat axis; wherein the first outside diameter isabout 5 inches; wherein the inside diameter is about 3 inches; whereinthe groove diameter is about 4 inches; and wherein the second outsidediameter is about 4.5 inches.

In a fourth aspect, there is provided a valve seat adapted to bedisposed within a fluid cylinder for a pump assembly, the valve seathaving a valve seat axis and includes a seat body, the seat bodyincludes an enlarged-diameter portion at one end thereof, theenlarged-diameter portion includes a first tapered external shoulder,the first tapered external shoulder defining a first angle from thevalve seat axis, and a frusto-conical surface extending at the firstangle from the valve seat axis, wherein the enlarged-diameter portiondefines a first cylindrical surface extending axially from thefrusto-conical surface, the first cylindrical surface defining a firstoutside diameter, wherein the seat body defines an outside surface, theoutside surface defining a second outside diameter that is less than thefirst outside diameter, wherein the outside surface of the seat body istapered at a second angle from the valve seat axis, and wherein thefrusto-conical surface is axially disposed between the outside surfaceand the first cylindrical surface; and a bore formed through the seatbody and through which fluid flows along the valve seat axis, the boredefining a second cylindrical surface, the second cylindrical surfacedefining an inside diameter that is less than the second outsidediameter.

In an exemplary embodiment, the first angle ranges from about 10 degreesto about 45 degrees measured from the valve seat axis; and wherein thesecond angle ranges from greater than 0 degrees to about 5 degreesmeasured from the valve seat axis.

In another exemplary embodiment, the first angle is about 30 degreesmeasured from the valve seat axis; and wherein the second angle rangesfrom greater than 0 degrees to about 5 degrees measured from the valveseat axis.

In yet another exemplary embodiment, the valve seat includes an annulargroove formed in the outside surface of the seat body, the annulargroove defining a groove diameter that is less than the second outsidediameter and greater than the inside diameter; and a sealing elementdisposed in the annular groove.

In an exemplary embodiment, the first angle is about 30 degrees measuredfrom the valve seat axis; wherein the second angle ranges from greaterthan 0 degrees to about 5 degrees measured from the valve seat axis;wherein the first outside diameter is about 5 inches; wherein the insidediameter is about 3 inches; wherein the groove diameter is about 4inches; and wherein the second outside diameter is about 4.5 inches.

In a fifth aspect, there is provided a method of producing a first pumpassembly based on a second pump assembly, the first and second pumpassemblies includes first and second fluid cylinders, respectively, andfirst and second valve seats, respectively, the first and second fluidcylinders includes first and second fluid passages formed therein,respectively, in which the first and second valve seats are adapted tobe disposed, respectively, the first and second fluid passages definingfirst and second inside diameters, respectively, the first and secondvalve seats defining first and second outside diameters, respectively,the method includes producing the first fluid cylinder, includes sizingthe first inside diameter to be less than the second outside diameter sothat the second valve seat is not permitted to be disposed in the firstfluid passage; and producing the first valve seat, includes sizing thefirst outside diameter so that: the first outside diameter is less thanthe second inside diameter; and a radial clearance would be definedbetween the first valve seat and an inside surface of the second fluidcylinder defined by the second fluid passage if the first valve seatwere to be disposed in the second fluid passage. As a result,operational incompatibility between parts of the first and second pumpassemblies is ensured and a long-term mix-up between parts is avoided.

In an exemplary embodiment, the method includes disposing the firstvalve seat in the first fluid passage.

In another exemplary embodiment, producing the first valve seat includesforming an enlarged-diameter portion, the enlarged-diameter portionincludes a tapered external shoulder, the tapered external shoulderdefining a first angle, the enlarged-diameter portion defining acylindrical surface, the cylindrical surface defining a third outsidediameter that is greater than the first outside diameter; whereinproducing the first fluid cylinder includes forming the first fluidpassage so that the first fluid passage defines a tapered internalshoulder, the tapered internal shoulder defining a second angle.

In yet another exemplary embodiment, producing the first valve seatfurther includes forming a bore through the first valve seat, the boredefining a third inside diameter that is less than the first outsidediameter; forming an annular groove in the first valve seat, the annulargroove defining a groove diameter that is less than the first outsidediameter and greater than the third inside diameter; and disposing asealing element in the annular groove.

In certain exemplary embodiments, the method includes disposing thefirst valve seat in the first fluid passage of the first cylinder sothat: the tapered external shoulder engages the tapered internalshoulder, and the sealing element sealingly engages the fluid cylinder.

In other exemplary embodiments, each of the first and second angles isabout 30 degrees relative to an axis; wherein the third outside diameteris about 5 inches; wherein the third inside diameter is about 3 inches;wherein the first inside diameter is about 4.5 inches; wherein thegroove diameter is about 4 inches; and wherein the first outsidediameter is about 4.5 inches.

Other aspects, features, and advantages will become apparent from thefollowing detailed description when taken in conjunction with theaccompanying drawings, which are a part of this disclosure and whichillustrate, by way of example, principles of the inventions disclosed.

DESCRIPTION OF FIGURES

The accompanying drawings facilitate an understanding of the variousembodiments.

FIG. 1 is an elevational view of a reciprocating pump assembly accordingto an exemplary embodiment, the pump assembly includes a fluid cylinderassembly.

FIG. 2 is a section view of the fluid cylinder assembly of FIG. 1according to an exemplary embodiment, the fluid cylinder assemblyincluding a fluid cylinder and inlet and outlet valves, the inlet andoutlet valves each including a valve seat.

FIG. 3 is an enlarged view of a portion of the section view of FIG. 2,according to an exemplary embodiment.

FIG. 4 is a section view of respective portions of the valve seat andthe fluid cylinder, according to another exemplary embodiment.

FIG. 5 is a section view of respective portions of the valve seat andfluid cylinder, according to yet another exemplary embodiment.

FIG. 6 is a section view of a valve according to another exemplaryembodiment, the valve including a valve seat.

FIG. 7 is a perspective view of the valve seat of FIG. 6, according toan exemplary embodiment.

FIG. 8 is a sectional view of the valve seat of FIGS. 6 and 7, accordingto an exemplary embodiment.

FIG. 9 is a sectional view of the valve of FIG. 6 disposed within thefluid cylinder of FIG. 2, according to an exemplary embodiment.

FIG. 10 is a flow chart illustration of a method of producing a new pumpassembly based on a previously sold pump assembly referred to as Legacyor the Legacy model, according to an exemplary embodiment.

FIG. 11 is a sectional view of a valve seat, according to anotherexemplary embodiment.

DETAILED DESCRIPTION

In an exemplary embodiment, as illustrated in FIG. 1, a reciprocatingpump assembly is generally referred to by the reference numeral 10 andincludes a power end portion 12 and a fluid end portion 14 operablycoupled thereto. The power end portion 12 includes a housing 16 in whicha crankshaft (not shown) is disposed, the crankshaft being operablycoupled to an engine or motor (not shown), which is adapted to drive thecrankshaft. The fluid end portion 14 includes a fluid end block or fluidcylinder 18, which is connected to the housing 16 via a plurality ofstay rods 20. The fluid cylinder 18 includes a fluid inlet passage 22and a fluid outlet passage 24, which are spaced in a parallel relation.A plurality of cover assemblies 26, one of which is shown in FIG. 1, isconnected to the fluid cylinder 18 opposite the stay rods 20. Aplurality of cover assemblies 28, one of which is shown in FIG. 1, isconnected to the fluid cylinder 18 opposite the fluid inlet passage 22.A plunger rod assembly 30 extends out of the housing 16 and into thefluid cylinder 18. In several exemplary embodiments, the pump assembly10 is freestanding on the ground, is mounted to a trailer that can betowed between operational sites, or is mounted to a skid.

In an exemplary embodiment, as illustrated in FIG. 2 with continuingreference to FIG. 1, the plunger rod assembly 30 includes a plunger 32,which extends through a bore 34 formed in the fluid cylinder 18, andinto a pressure chamber 36 formed in the fluid cylinder 18. In severalexemplary embodiments, a plurality of parallel-spaced bores may beformed in the fluid cylinder 18, with one of the bores being the bore34, a plurality of pressure chambers may be formed in the fluid cylinder18, with one of the pressure chambers being the pressure chamber 36, anda plurality of parallel-spaced plungers may extend through respectiveones of the bores and into respective ones of the pressure chambers,with one of the plungers being the plunger 32. At least the bore 34, thepressure chamber 36, and the plunger 32 together may be characterized asa plunger throw. In several exemplary embodiments, the reciprocatingpump assembly 10 includes three plunger throws (i.e., a triplex pumpassembly), or includes four or more plunger throws.

As shown in FIG. 2, the fluid cylinder 18 includes inlet and outletfluid passages 38 and 40 formed therein, which are generally coaxialalong a fluid passage axis 42. Under conditions to be described below,fluid is adapted to flow through the inlet and outlet fluid passages 38and 40 and along the fluid passage axis 42. The fluid inlet passage 22is in fluid communication with the pressure chamber 36 via the inletfluid passage 38. The pressure chamber 36 is in fluid communication withthe fluid outlet passage 24 via the outlet fluid passage 40. The fluidinlet passage 38 includes an enlarged-diameter portion 38 a and areduced-diameter portion 38 b extending downward therefrom. Theenlarged-diameter portion 38 a defines a tapered internal shoulder 43and thus a frusto-conical surface 44 of the fluid cylinder 18. Thereduced-diameter portion 38 b defines an inside surface 46 of the fluidcylinder 18. Similarly, the fluid outlet passage 40 includes anenlarged-diameter portion 40 a and a reduced-diameter portion 40 bextending downward therefrom. The enlarged-diameter portion 40 a definesa tapered internal shoulder 48 and thus a frusto-conical surface 50 ofthe fluid cylinder 18. The reduced-diameter portion 40 b defines aninside surface 52 of the fluid cylinder 18.

An inlet valve 54 is disposed in the fluid passage 38, and engages atleast the frusto-conical surface 44 and the inside surface 46.Similarly, an outlet valve 56 is disposed in the fluid passage 40, andengages at least the frusto-conical surface 50 and the inside surface52. In an exemplary embodiment, each of valves 54 and 56 is aspring-loaded valve that is actuated by a predetermined differentialpressure thereacross.

A counterbore 58 is formed in the fluid cylinder 18, and is generallycoaxial with the fluid passage 42. The counterbore 58 defines aninternal shoulder 58 a and includes an internal threaded connection 58 badjacent the internal shoulder 58 a. A counterbore 60 is formed in thefluid cylinder 18, and is generally coaxial with the bore 34 along anaxis 62. The counterbore 60 defines an internal shoulder 60 a andincludes an internal threaded connection 60 b adjacent the internalshoulder 60 a. In several exemplary embodiments, the fluid cylinder 18may include a plurality of parallel-spaced counterbores, one of whichmay be the counterbore 58, with the quantity of counterbores equalingthe quantity of plunger throws included in the pump assembly 10.Similarly, in several exemplary embodiments, the fluid cylinder 18 mayinclude another plurality of parallel-spaced counterbores, one of whichmay be the counterbore 60, with the quantity of counterbores equalingthe quantity of plunger throws included in the pump assembly 10.

A plug 64 is disposed in the counterbore 58, engaging the internalshoulder 58 a and sealingly engaging an inside cylindrical surfacedefined by the reduced-diameter portion of the counterbore 58. Anexternal threaded connection 66 a of a fastener 66 is threadably engagedwith the internal threaded connection 58 b of the counterbore 58 so thatan end portion of the fastener 66 engages the plug 64. As a result, thefastener 66 sets or holds the plug 64 in place against the internalshoulder 58 a defined by the counterbore 58, thereby maintaining thesealing engagement of the plug 64 against the inside cylindrical surfacedefined by the reduced-diameter portion of the counterbore 58. The coverassembly 28 shown in FIGS. 1 and 2 includes at least the plug 64 and thefastener 66. In an exemplary embodiment, the cover assembly 28 may bedisconnected from the fluid cylinder 18 to provide access to, forexample, the counterbore 58, the pressure chamber 36, the plunger 32,the fluid passage 40 or the outlet valve 56. The cover assembly 28 maythen be reconnected to the fluid cylinder 18 in accordance with theforegoing. In several exemplary embodiments, the pump assembly 10 mayinclude a plurality of plugs, one of which is the plug 64, and aplurality of fasteners, one of which is the fastener 66, with therespective quantities of plugs and fasteners equaling the quantity ofplunger throws included in the pump assembly 10.

A plug 68 is disposed in the counterbore 60, engaging the internalshoulder 60 a and sealingly engaging an inside cylindrical surfacedefined by the reduced-diameter portion of the counterbore 60. In anexemplary embodiment, the plug 68 maybe characterized as a suctioncover. An external threaded connection 70 a of a fastener 70 isthreadably engaged with the internal threaded connection 60 b of thecounterbore 60 so that an end portion of the fastener 70 engages theplug 68. As a result, the fastener 70 sets or holds the plug 68 in placeagainst the internal shoulder 60 a defined by the counterbore 60,thereby maintaining the sealing engagement of the plug 68 against theinside cylindrical surface defined by the reduced-diameter portion ofthe counterbore 60. The cover assembly 26 shown in FIGS. 1 and 2includes at least the plug 68 and the fastener 70. In an exemplaryembodiment, the cover assembly 26 may be disconnected from the fluidcylinder 18 to provide access to, for example, the counterbore 60, thepressure chamber 36, the plunger 32, the fluid passage 38, or the inletvalve 54. The cover assembly 26 may then be reconnected to the fluidcylinder in accordance with the foregoing. In several exemplaryembodiments, the pump assembly 10 may include a plurality of plugs, oneof which is the plug 68, and a plurality of fasteners, one of which isthe fastener 70, with the respective quantities of plugs and fastenersequaling the quantity of plunger throws included in the pump assembly10.

A valve spring retainer 72 is disposed in the enlarged-diameter portion38 a of the fluid passage 38. The valve spring retainer 72 is connectedto the end portion of the plug 68 opposite the fastener 70. In anexemplary embodiment, and as shown in FIG. 2, the valve spring retainer72 is connected to the plug 68 via a hub 74, which is generally coaxialwith the axis 62.

In an exemplary embodiment, as illustrated in FIG. 3 with continuingreference to FIGS. 1 and 2, the inlet valve 54 includes a valve seat 76and a valve member 78 engaged therewith. The valve seat 76 includes aseat body 80 having an enlarged-diameter portion 82 at one end thereof.The enlarged-diameter portion 82 of the seat body 80 is disposed in theenlarged-diameter portion 38 a of the fluid passage 38. A bore 83 isformed through the seat body 80. The valve seat 76 has a valve seat axis84, which is aligned with the fluid passage axis 42 when the inlet valve54 is disposed in the fluid passage 38, as shown in FIG. 3. Underconditions to be described below, fluid flows through the bore 83 andalong the valve seat axis 84. The bore 83 defines an inside surface 85of the seat body 80. An outside surface 86 of the seat body 80 contactsthe inside surface 46 defined by the fluid passage 38. A sealingelement, such as an o-ring 88, is disposed in an annular groove 90formed in the outside surface 86. The o-ring 88 sealingly engages theinside surface 46. The enlarged-diameter portion 82 includes a taperedexternal shoulder 91 and thus defines a frusto-conical surface 92, whichextends angularly upward from the outside surface 86. The portion 82further defines a cylindrical surface 94, which extends axially upwardfrom the extent of the frusto-conical surface 92. The frusto-conicalsurface 92 is axially disposed between the outside surface 86 and thecylindrical surface 94. The portion 82 further defines a tapered surface96, which extends angularly upward from the inside surface 85. In anexemplary embodiment, the tapered surface 96 extends at an angle fromthe valve seat axis 84, which angle ranges from about 15 degrees toabout 45 degrees. The seat body 80 of the valve seat 76 is disposedwithin the reduced-diameter portion 38 b of the fluid passage 38 so thatthe outside surface 86 of the seat body 80 engages the inside surface 46of the fluid cylinder 18. In an exemplary embodiment, the seat body 80forms an interference fit, or is press fit, in the portion 38 b of thefluid passage 38 so that the valve seat 76 is prevented from beingdislodged from the fluid passage 38.

The valve member 78 includes a central stem 98, from which a valve body100 extends radially outward. An outside annular cavity 102 is formed inthe valve body 100. A seal 104 extends within the cavity 102, and isadapted to sealingly engage the tapered surface 96 of the valve seat 76,under conditions to be described below. A plurality ofcircumferentially-spaced legs 106 extend angularly downward from thecentral stem 98, and slidably engage the inside surface 85 of the seatbody 80. In several exemplary embodiments, the plurality of legs 106 mayinclude two, three, four, five, or greater than five, legs 106. A lowerend portion of a spring 108 is engaged with the top of the valve body100 opposite the central stem 98. The valve member 78 is movable,relative to the valve seat 76 and thus the fluid cylinder 18, between aclosed position (shown in FIG. 3) and an open position (not shown),under conditions to be described below.

In an exemplary embodiment, the seal 104 is molded in place in the valvebody 100. In an exemplary embodiment, the seal 104 is preformed and thenattached to the valve body 100. In several exemplary embodiments, theseal 104 is composed of one or more materials such as, for example, adeformable thermoplastic material, a urethane material, afiber-reinforced material, carbon, glass, cotton, wire fibers, cloth,and/or any combination thereof. In an exemplary embodiment, the seal 104is composed of a cloth which is disposed in a thermoplastic material,and the cloth may include carbon, glass, wire, cotton fibers, and/or anycombination thereof. In several exemplary embodiments, the seal 104 iscomposed of at least a fiber-reinforced material, which can prevent orat least reduce delamination. In an exemplary embodiment, the seal 104has a hardness of 95 A durometer or greater, or a hardness of 69 Ddurometer or greater. In several exemplary embodiments, the valve body100 is much harder and more rigid than the seal 104.

The outlet valve 56 is identical to the inlet valve 54 and thereforewill not be described in further detail. Features of the outlet valve 56that are identical to corresponding features of the inlet valve 54 willbe given the same reference numerals as that of the inlet valve 54. Thevalve seat axis 84 of the outlet valve 56 is aligned with each of thefluid passage axis 42 and the valve seat axis 84 of the inlet valve 54.The outlet valve 56 is disposed in the fluid passage 40, and engages thefluid cylinder 18, in a manner that is identical to the manner in whichthe inlet valve 54 is disposed in the fluid passage 38, and engages thefluid cylinder 18, with one exception. This one exception involves thespring 108 of the outlet valve 56; more particularly, the upper portionof the spring 108 of the outlet valve 56 is compressed against thebottom of the plug 64, rather than being compressed against a componentthat corresponds to the valve spring retainer 72, against which theupper portion of the spring 108 of the inlet valve 54 is compressed.

In operation, in an exemplary embodiment, with continuing reference toFIGS. 1-3, the plunger 32 reciprocates within the bore 34, reciprocatingin and out of the pressure chamber 36. That is, the plunger 32 movesback and forth horizontally, as viewed in FIG. 2, away from and towardsthe fluid passage 42. In an exemplary embodiment, the engine or motor(not shown) drives the crankshaft (not shown) enclosed within thehousing 16, thereby causing the plunger 32 to reciprocate within thebore 34 and thus in and out of the pressure chamber 36.

As the plunger 32 reciprocates out of the pressure chamber 36, the inletvalve 54 is opened. More particularly, as the plunger 32 moves away fromthe fluid passage 42, the pressure inside the pressure chamber 36decreases, creating a differential pressure across the inlet valve 54and causing the valve member 78 to move upward, as viewed in FIGS. 2 and3, relative to the valve seat 76 and the fluid cylinder 18. As a resultof the upward movement of the valve member 78, the spring 108 iscompressed between the valve body 100 and the valve spring retainer 72,the seal 104 disengages from the tapered surface 96, and the inlet valve54 is thus placed in its open position. Fluid in the fluid inlet passage22 flows along the fluid passage axis 42 and through the fluid passage38 and the inlet valve 54, being drawn into the pressure chamber 36. Toflow through the inlet valve 54, the fluid flows through the bore 83 ofthe valve seat 76 and along the valve seat axis 84. During the fluidflow through the inlet valve 54 and into the pressure chamber 36, theoutlet valve 56 is in its closed position, with the seal 104 of thevalve member 78 of the outlet valve 56 engaging the tapered surface 96of the valve seat 76 of the outlet valve 56. Fluid continues to be drawninto the pressure chamber 36 until the plunger 32 is at the end of itsstroke away from the fluid passage 42. At this point, the differentialpressure across the inlet valve 54 is such that the spring 108 of theinlet valve 54 is not further compressed, or begins to decompress andextend, forcing the valve member 78 of the inlet valve 54 to movedownward, as viewed in FIGS. 2 and 3, relative to the valve seat 76 andthe fluid cylinder 18. As a result, the inlet valve 54 is placed in, orbegins to be placed in, its closed position, with the seal 104 sealinglyengaging, or at least moving towards, the tapered surface 96.

As the plunger 32 moves into the pressure chamber 36 and thus towardsthe fluid passage 42, the pressure within the pressure chamber 36 beginsto increase. The pressure within the pressure chamber 36 continues toincrease until the differential pressure across the outlet valve 56exceeds a predetermined set point, at which point the outlet valve 56opens and permits fluid to flow out of the pressure chamber 36, alongthe fluid passage axis 42 and through the fluid passage 40 and theoutlet valve 56, and into the fluid outlet passage 24. As the plunger 32reaches the end of its stroke towards the fluid passage 42 (i.e., itsdischarge stroke), the inlet valve 54 is in, or is placed in, its closedposition, with the seal 104 sealingly engaging the tapered surface 96.

The foregoing is repeated, with the reciprocating pump assembly 10pressurizing the fluid as the fluid flows from the fluid inlet passage22 and to the fluid outlet passage 24 via the pressure chamber 36. In anexemplary embodiment, the pump assembly 10 is a single-actingreciprocating pump, with fluid being pumped across only one side of theplunger 32.

In an exemplary embodiment, during the above-described operation of thereciprocating pump assembly 10, the taper of each of the surfaces 44 and92 balances the loading forces applied thereagainst. In an exemplaryembodiment, the loading is distributed across the surface 44 and 92,reducing stress concentrations. In an exemplary embodiment, the stressesin the valve seat 76, in the vicinity of the fillet interface betweenthe surfaces 86 and the 92, are balanced with the stresses in the fluidcylinder 18, in the vicinity of the round interface between the surfaces46 and 44. As a result, these stresses are reduced. In an exemplaryembodiment, the taper of each of the surfaces 44 and 92 permits theoutside diameter of the seat body 80 of the inlet valve 54 to bereduced, thereby also permitting a relative smaller service port, aswell relatively smaller cross-bore diameters within the fluid cylinder18. In an exemplary embodiment, the taper of each of the surfaces 44 and92 reduces the extraction force necessary to remove the valve seat 76from the fluid passage 38.

In an exemplary embodiment, as illustrated in FIG. 4 with continuingreference to FIGS. 1-3, a taper angle 110 is defined by the taperedexternal shoulder 91 and thus the frusto-conical surface 92. A taperangle 112 is defined by the tapered internal shoulder 43 and thus thefrusto-conical surface 44. Each of the taper angles 110 and 112 may bemeasured from the fluid passage axis 42 and the valve seat axis 84aligned therewith. In an exemplary embodiment, the taper angles 110 and112 are equal, and range from about 10 degrees to about 45 degreesmeasured from the fluid passage axis 42 and the valve seat axis 84aligned therewith. In an exemplary embodiment, the taper angles 110 and112 range from about 20 degrees to 40 degrees measured from the fluidpassage axis 42 and the valve seat axis 84 aligned therewith. In anexemplary embodiment, the taper angles 110 and 112 range from about 25to 35 degrees measured from the fluid passage axis 42 and the valve seataxis 84 aligned therewith. In an exemplary embodiment, the taper angles110 and 112 are equal, and each of the taper angles 110 and 112 is about30 degrees measured from the fluid passage axis 42 and the valve seataxis 84 aligned therewith. In an exemplary embodiment, the taper angles110 and 112 are not equal. As shown in FIG. 4, a frusto-conical gap orregion 114 may be defined between the surfaces 44 and 92. Moreover, aradial clearance 116 is defined between the outside cylindrical surface94 of the valve seat 76 and an inside surface 118 of the fluid cylinder18, the surface 118 being defined by the enlarged-diameter portion 38 aof the fluid passage 38. In an exemplary embodiment, the region 114 maybe omitted and the surface 92 may abut the surface 44. In an exemplaryembodiment, material may be disposed in the region 114 to absorb,transfer and/or distribute loads between the surfaces 44 and 92.

As shown in FIG. 4, at least the end portion of the body 80 opposite theenlarged-diameter portion 82 is tapered at a taper angle 120 from thefluid passage axis 42 and the valve seat axis 84 aligned therewith. Inan exemplary embodiment, the taper angle 120 ranges from about 0 degreesto about 5 degrees measured from the fluid passage axis 42 and the valveseat axis 84 aligned therewith. In an exemplary embodiment, the taperangle 120 ranges from about 1 degree to about 4 degrees measured fromthe fluid passage axis 42 and the valve seat axis 84 aligned therewith.In an exemplary embodiment, the taper angle 120 ranges from about 1degree to about 3 degrees measured from the fluid passage axis 42 andthe valve seat axis 84 aligned therewith. In an exemplary embodiment,the taper angle 120 is about 2 degrees measured from the fluid passageaxis 42 and the valve seat axis 84 aligned therewith. In an exemplaryembodiment, the taper angle 120 is about 1.8 degrees measured from thefluid passage axis 42 and the valve seat axis 84 aligned therewith. Inan exemplary embodiment, instead of, or in addition to the end portionof the body 80 opposite the enlarged-diameter portion 82 being tapered,the inside surface 46 of the fluid cylinder 18 is tapered at the taperangle 120. In an exemplary embodiment, an interference fit may be formedbetween the body 80 and the inside surface 46, thereby holding the valveseat 76 in place in the fluid cylinder. In several exemplaryembodiments, instead of using an interference fit in the fluid passage38, a threaded connection, a threaded nut, and/or a snap-fit mechanismmay be used to hold the valve seat 76 in place in the fluid cylinder 18.

In an exemplary embodiment, during operation of the pump assembly 10using the embodiment of the inlet valve 54 illustrated in FIG. 4, thesurfaces 92 and 44 provide load balancing, with loading on theenlarged-diameter portion 82 of the valve seat 76 being distributed andtransferred to the surface 44 of the fluid cylinder 18, via either thepressing of the surface 92 against the surface 44 or intermediatematerial(s) disposed therebetween.

In an exemplary embodiment, as illustrated in FIG. 5 with continuingreference to FIGS. 1-4, a fillet surface 122 of the fluid cylinder 18 isdefined by the enlarged-diameter portion 38 a of the fluid passage 38.The fillet surface 122 extends between the frusto-conical surface 44 andthe inside surface 118. As shown in FIG. 5, each of the frusto-conicalsurfaces 92 and 44 is tapered at a taper angle 123, which may bemeasured from the fluid passage axis 42 and the valve seat axis 84aligned therewith. In an exemplary embodiment, the taper angle 123ranges from about 10 degrees to about 45 degrees measured from the fluidpassage axis 42 and the valve seat axis 84 aligned therewith. In anexemplary embodiment, the taper angle 123 ranges from about greater than10 degrees to about 30 degrees measured from the fluid passage axis 42and the valve seat axis 84 aligned therewith. In an exemplaryembodiment, the taper angle 123 ranges from about 12 degrees to about 20degrees measured from the fluid passage axis 42 and the valve seat axis84 aligned therewith. In an exemplary embodiment, the taper angle 123 isabout 14 degrees measured from the fluid passage axis 42 and the valveseat axis 84 aligned therewith. In an exemplary embodiment, the surface92 and 44 may be tapered at respective angles that are not equal. Thesurface 92 abuts the surface 44. As shown in FIG. 5, the groove 90 andthe o-ring 88 are omitted in favor of an annular groove 124 and ano-ring 126, respectively. The annular groove 124 is formed in thefrusto-conical surface 92, and the o-ring 126 is disposed in the annulargroove 124. The o-ring 126 sealingly engages the frusto-conical surface44.

In an exemplary embodiment, during operation of the pump assembly 10using the embodiment of the inlet valve 54 illustrated in FIG. 5, loadsapplied to the valve seat 76 are distributed and transferred to thefluid cylinder 18 via, at least in part, the load balancing provided bythe abutment of the surface 92 against the surface 44.

In an exemplary embodiment, during operation of the pump assembly 10using any of the foregoing embodiments of the inlet valve 54, downwardlydirected axial loads along the fluid passage 42 are applied against thetop of the valve body 100. This loading is usually greatest as theplunger 32 moves towards the fluid passage 42 and the outlet valve 56opens and permits fluid to flow out of the pressure chamber 36, throughthe fluid passage 40 and the outlet valve 56, and into the fluid outletpassage 24. As the plunger 32 reaches the end of its stroke towards thefluid passage 42 (its discharge stroke), the inlet valve 54 is in, or isplaced in, its closed position, and the loading applied to the top ofthe valve body 100 is transferred to the seal 104 via the valve body100. The loading is then transferred to the valve seat 76 via the seal104, and then is distributed and transferred to the tapered internalshoulder 43 of the fluid cylinder 18 via either the engagement of thesurface 92 against the surface 44 or intermediate material(s) disposedtherebetween. The tapering of the surfaces 92 and 44 facilitates thisdistribution and transfer of the downwardly directed axial loading tothe fluid cylinder 18 in a balanced manner, thereby reducing stressconcentrations in the fluid cylinder 18 and the valve seat 76.

In an exemplary embodiment, as illustrated in FIGS. 6-8 with continuingreference to FIGS. 1-5, an inlet valve is generally referred to by thereference numeral 128 and includes several parts that are identical tocorresponding parts of the inlet valve 54, which identical parts aregiven the same reference numerals. The inlet valve 128 includes a valveseat 129. The valve seat 129 includes several features that areidentical to corresponding features of the valve seat 76, whichidentical features are given the same reference numerals. An annularnotch 130 is formed in the valve seat 128 at the intersection of thesurfaces 86 and 92.

As shown in FIG. 8, a taper angle 132 is defined by the external taperedshoulder 93 and thus the frusto-conical surface 94. The taper angle 132may be measured from the valve seat axis 84. In an exemplary embodiment,the taper angle 132 is about 30 degrees measured from the valve seataxis 84. In an exemplary embodiment, the taper angle 132 ranges fromabout 10 degrees to about 45 degrees measured from the valve seat axis84. In an exemplary embodiment, the taper angle 132 ranges from about 20degrees to about 40 degrees measured from the valve seat axis 84. In anexemplary embodiment, the taper angle 132 ranges from about 25 to about35 degrees measured from the valve seat axis 84. The cylindrical surface94 defined by the enlarged-diameter portion 82 of the valve seat 129defines an outside diameter 134. In an exemplary embodiment, the outsidediameter 134 is about 5 inches. In an exemplary embodiment, the outsidediameter 134 is about 5.06 inches. The inside surface 85 of the seatbody 80 defined by the bore 83 formed therethrough defines an insidediameter 136. In an exemplary embodiment, the inside diameter 136 rangesfrom about 3 inches to about 3.5 inches. In an exemplary embodiment, theinside diameter 136 is about 3.27 inches. An annular surface 138 of theseat body 80 is defined by the annular groove 90. A groove diameter 140is defined by the annular surface 138. In an exemplary embodiment, thegroove diameter 140 ranges from about 4 inches to about 4.5 inches. Inan exemplary embodiment, the groove diameter 140 is about 4.292 inches.In an exemplary embodiment, an outside diameter 142 is defined by theoutside surface 86 of the seat body 80 at an axial location therealongadjacent the annular notch 130, or at least in the vicinity of theintersection between the surfaces 86 and 92. In an exemplary embodiment,the outside diameter 142 ranges from about 4 inches to about 5 inches.In an exemplary embodiment, the outside diameter 142 ranges from about4.5 inches to about 5 inches. In an exemplary embodiment, the outsidediameter 142 ranges from about 4.5 inches to about 4.6 inches. In anexemplary embodiment, the outside diameter 142 is about 4.565 inches.The outside surface 86 is tapered radially inward beginning at the axiallocation of the outside diameter 142 and ending at the end of the body80 opposite the enlarged-diameter portion 82, thereby defining a taperangle 144 from the valve seat axis 84. In an exemplary embodiment, thetaper angle 144 ranges from about 0 degrees to about 5 degrees measuredfrom the valve seat axis 84. In an exemplary embodiment, the taper angle144 ranges from greater than 0 degrees to about 5 degrees measured fromthe valve seat axis 84. In an exemplary embodiment, the taper angle 120is about 2 degrees measured from the valve seat axis 84. In an exemplaryembodiment, the taper angle 144 is about 1.8 degrees measured from thevalve seat axis 84.

In an exemplary embodiment, as illustrated in FIG. 9 with continuingreference to FIGS. 1-8, the inlet valve 54 is omitted from the pumpassembly 10 in favor of the inlet valve 128, which is disposed in thefluid passage 38. The tapered external shoulder 91 of the valve seat 129engages the tapered internal shoulder 43 of the fluid cylinder 18. Thus,the frusto-conical surface 92 engages the frusto-conical surface 44. Inan exemplary embodiment, the tapered internal shoulder 43 defines ataper angle from the fluid passage axis 42 that is equal to the taperangle 132. In an exemplary embodiment, the tapered internal shoulder 43defines a taper angle that is equal to the taper angle 132, and thetaper angle 132 ranges from about 10 degrees to about 45 degreesmeasured from the valve seat axis 84. In an exemplary embodiment, thetapered angle 132 ranges from about 20 degrees to 45 degrees measuredfrom the valve seat axis 84. In an exemplary embodiment, the taperedangle 132 ranges from about 25 degrees to 35 degrees measured from thevalve seat axis 84. In an exemplary embodiment, the tapered internalshoulder 43 defines a taper angle that is equal to the taper angle 132,and the taper angle 132 is about 30 degrees measured from the valve seataxis 84. The o-ring 88 sealingly engages the inside surface 46 of thefluid cylinder 18. The outside surface 86 of the body 80 of the valveseat 129 of the inlet valve 128 engages the inside surface 46 of thefluid cylinder 18. In an exemplary embodiment, at least thereduced-diameter portion 38 b of the fluid passage 38 is tapered suchthat an inside diameter 146 defined by the portion 38 b decreases alongthe fluid passage 42 in an axial direction away from theenlarged-diameter portion 38 a. In an exemplary embodiment, at an axiallocation corresponding to the intersection between the surfaces 46 and44, the inside diameter 146 ranges from about 4 inches to about 5inches. In an exemplary embodiment, at an axial location correspondingto the intersection between the surfaces 46 and 44, the inside diameter146 ranges from about 4.5 inches to about 5 inches. In an exemplaryembodiment, at an axial location corresponding to the intersectionbetween the surfaces 46 and 44, the inside diameter 146 ranges fromabout 4.5 inches to about 4.6 inches. In an exemplary embodiment, at anaxial location corresponding to the intersection between the surfaces 46and 44, the inside diameter 146 is about 4.553 inches. In an exemplaryembodiment, an interference fit is formed between the outside surface 86and the inside surface 46, thereby preventing the valve seat 129 frombeing dislodged from the fluid passage 38.

In an exemplary embodiment, the operation of the inlet valve 129 duringthe operation of the pump assembly 10 is identical to the operation ofthe inlet valve 54. Therefore, the operation of the inlet valve 129during the operation of the pump assembly 10 will not be described indetail.

In an exemplary embodiment, the inlet valve 54 may be omitted from thepump assembly 10 in favor of the inlet valve 128, and the outlet valve56 may be omitted from the pump assembly 10 in favor of an outlet valvethat is identical to the inlet valve 128. In an exemplary embodiment,the operation of the pump assembly 10 using the inlet valve 128, and anoutlet valve that is identical to the inlet valve 128, is identical tothe above-described operation of the pump assembly 10 using the inletvalve 54 and the outlet valve 56.

In several experimental exemplary embodiments, experimental finiteelement analyses were conducted on an Experimental Baseline Embodiment(simulating a previous pump assembly that may be referred to as Legacyor the Legacy model) of a combination of the valve seat 129 and thefluid cylinder 18, and also on three Experimental Exemplary Embodimentsof combinations of the valve seat 129 and the fluid cylinder 18.Experimental stresses were determined at three points in each of theExperimental Exemplary Embodiments 1, 2 and 3, which points are shown inFIG. 9, namely Point A, which is on the fluid cylinder 18 at about theintersection between the surfaces 44 and 118; Point B, which is on thevalve seat 129 at about the nadir defined by the annular notch 130; andPoint C, which is on the valve seat 129 at about the intersectionbetween the axially-extending surface of the fluid cylinder 18 definedby the annular groove 90 and the lower radially-extending surface of thefluid cylinder 18 defined by the annular groove 90.

For the Experimental Baseline Embodiment, the taper angle 132 was 90degrees, the inside diameter 136 was 3.27 inches, and the outsidediameter 134 was 5.06 inches. For Experimental Exemplary Embodiments 1,2 and 3, the taper angle 132 was 30 degrees, the inside diameter 136 was3.27 inches, and the outside diameter 134 was 5.06 inches. These valuescorrespond to the plunger 32 being a 4.5-inch plunger, that is, theplunger 32 having an outside diameter of about 4.5 inches. Additionaldimensions of the Experimental Exemplary Embodiments are set forth inTable I below (these values also correspond to the plunger 32 being a4.5-inch plunger):

TABLE I Dimensions Experimental Experimental Experimental ExperimentalBaseline Exemplary Exemplary Exemplary Embodiment Embodiment 1Embodiment 2 Embodiment 3 Inside diameter 4.641 4.641 4.596 4.553 146(inches) Groove diameter 4.380 4.380 4.335 4.292 140 (inches) Outsidediameter 4.653 4.653 4.608 4.565 142 (inches)

The stress response results of the experimental finite element analyses,under a simulated condition corresponding to the pressure chamber 36being pressurized at 16,800 psi, are set forth in Table II below:

TABLE II Stress Responses at 16,800 psi Experimental ExperimentalExperimental Experimental Baseline Exemplary Exemplary ExemplaryEmbodiment Embodiment 1 Embodiment 2 Embodiment 3 Von-mises stress -Point 58,632.6 41,860.4 41,754.2 41,658.5 A (psi) Von-mises stress -Point 106,517 59,282.6 58,571.6 58,312.3 B (psi) Von-mises stress -Point 52,330 81,584.5 81,849.1 81,216.9 C (psi) 1st principal stress -Point 49,716.1 26,393.5 26,148.7 25,944.3 A (psi) 1st principal stress -Point 86,958.5 22,320.2 20,384.6 19,046.2 B (psi)

The stress response results of the experimental finite element analyses,under a simulated condition corresponding to the pressure chamber 36being pressurized at 19,286 psi, are set forth in Table III below:

TABLE III Stress Responses at 19,286 psi Experimental ExperimentalExperimental Experimental Baseline Exemplary Exemplary ExemplaryEmbodiment Embodiment 1 Embodiment 2 Embodiment 3 Von-mises stress -Point 69,340.0 47,815.8 47,697.2 47,591.5 A (psi) Von-mises stress -Point 123,150 77,791.6 76,387.5 75,565.0 B (psi) Von-mises stress -Point 50,763 76,511.0 77,434.2 77,433.5 C (psi) 1st principal stress -Point 59,885.5 29,796.5 29,546.8 29,340.3 A (psi) 1st principal stress -Point 110,138 42,530.0 39,977.6 38,101.2 B (psi)

As indicated in Tables II and III above, as the experimental outsidediameter 142 of the experimental valve seat 129 was reduced, theexperimental stress responses decreased. This was an unexpected result.The decreases in experimental stress responses for Points B and C on theExperimental Exemplary Embodiments of the valve seat 129 were unexpectedbecause it was expected that, as the cross-sectional area of the valveseat 129 (corresponding to a cross-section of the body 80 that is belowthe enlarged-diameter portion 82 and is perpendicular to the valve seataxis 84) decreased, the stress responses at Points B and C wouldincrease. Unexpected experimental results were achieved with the taperangle 132 being about 30 degrees, the outside diameter 134 being about 5inches, the inside diameter 136 being about 3 inches, the groovediameter being about 4 inches, and, unexpectedly, the outside diameter142 being less than 4.6 inches. Based on these unexpected results, itwas determined that a new pump assembly 10 could be produced based onthe pump assembly 10, with the diameters 146, 140 and 142 of the newpump assembly 10 being sufficiently less than the diameters 146, 140 and142 of the previous pump assembly 10 so that the valve seat 129 of thenew pump assembly 10 would not be operationally compatible with thefluid cylinder 18 of the previous pump assembly 10, and so that thevalve seat 129 of the previous pump assembly 10 would not beoperationally compatible with the fluid cylinder 18 of the new pumpassembly 10, thereby preventing any mix-up of parts between the new andprevious pump assemblies 10. These goals of operational incompatibilityand long-term mix-up prevention could be achieved while unexpectedlyimproving the stress responses of the new pump assembly 10.

In an exemplary embodiment, as illustrated in FIG. 10 with continuingreference to FIGS. 1-9, a method of producing a new pump assembly basedon the previous pump assembly is generally referred to by the referencenumeral 150 and referred to herein as Legacy or the Legacy model. Themethod 150 includes a step 152 at which a replacement fluid cylinder isproduced, the replacement fluid cylinder including a replacement fluidpassage formed therein, the replacement fluid passage defining areplacement inside diameter. The step 152 includes sizing thereplacement inside diameter so that a valve seat sized and shaped forthe Legacy pump assembly is not permitted to be disposed in thereplacement fluid passage. Since the Legacy valve seat is not permittedto be disposed in the replacement fluid passage, the parts areoperationally incompatible and a mix-up of the parts is avoided. At step154, a replacement valve seat is produced, the replacement valve seatdefining a replacement outside diameter. The step 154 includes sizingthe replacement outside diameter so that the replacement outsidediameter is less than a Legacy inside diameter defined by a Legacy fluidpassage formed in a Legacy fluid cylinder of the Legacy model pumpassembly, and so that a radial clearance is defined between thereplacement valve seat and an inside surface of the Legacy fluidcylinder defined by the Legacy fluid passage if the replacement valveseat is disposed in the Legacy fluid passage. As a result, if thereplacement valve seat is disposed in the Legacy fluid passage and theLegacy pump assembly is subsequently operated, the Legacy pump assemblywill not be able to hold pressure and this pressure deficiency will bequickly and easily detected, prompting troubleshooting and the detectionof the operational incompatibility, and mix-up, of the parts. Thus, along-term mix-up of the parts is avoided. At step 156, the replacementvalve seat is disposed in the replacement fluid passage of thereplacement fluid cylinder. In several exemplary embodiments, the method150 includes additional steps in which the replacement pump assembly isassembled in accordance with the foregoing description of the pumpassembly 10. In several exemplary embodiments, each of the replacementand Legacy fluid cylinders may be identical to the fluid cylinder 18 asillustrated in FIG. 9, and each of the replacement and Legacy valveseats may be identical to the valve seat 129 as illustrated in FIGS. 8and 9, with at least two exceptions. First, the inside diameter 146 ofthe replacement fluid cylinder is less than the outside diameter 142 ofthe Legacy valve seat so that the Legacy valve seat is not permitted tobe disposed in the portion 38 b of the fluid passage 38 of thereplacement fluid cylinder. Second, the outside diameter 142 of thereplacement valve seat is less than the inside diameter 146 of theLegacy fluid cylinder so that a radial clearance is defined between thesurface 86 of the replacement valve seat and the inside surface 46 ofthe Legacy fluid cylinder.

In an exemplary embodiment, as illustrated in FIG. 11 with continuingreference to FIGS. 1-10, a valve seat is generally referred to by thereference numeral 160 and includes several features that are identicalto corresponding features of the valve seat 129, which identicalfeatures are given the same reference numerals. The annular notch 130 ofthe valve seat 129 is omitted in favor of an annular channel 162. In anexemplary embodiment, the taper angle 132 is about 30 degrees measuredfrom the axis 84. In an exemplary embodiment, the outside diameter 134is about 4.5 inches. In an exemplary embodiment, the inside diameter 136is about 3 inches. In an exemplary embodiment, the groove diameter 140is about 3.5 inches. In an exemplary embodiment, the outside diameter142 is about 3.5 inches. In an exemplary embodiment, the taper angle 144is about 1.8 degrees measured from the axis 84. In an exemplaryembodiment, the taper angle 132 ranges from about 10 degrees to about 45degrees measured from the axis 84. In an exemplary embodiment, theoutside diameter 134 ranges from about 4 inches to about 5 inches. In anexemplary embodiment, the inside diameter 136 ranges from about 2.5inches to about 3.5 inches. In an exemplary embodiment, the groovediameter 140 ranges from about 3 inches to about 4 inches. In anexemplary embodiment, the outside diameter 142 ranges from about 3inches to about 4 inches. In an exemplary embodiment, the taper angle144 ranges from greater than 0 degrees to about 5 degrees. In severalexemplary embodiments, the valve seat 129 may be used in one or more ofthe valves 54, 56 and 128.

In several exemplary embodiments, variations may be made to the valvemember 100, or the valve member 100 may be omitted in favor of anothervalve member that does not include the plurality of legs 106. In severalexemplary embodiments, the valves 54, 56 and 128 may be configured tooperate in the presence of highly abrasive fluids, such as drilling mud,and at relatively high pressures, such as at pressures of up to about15,000 psi or greater. In several exemplary embodiments, instead of, orin addition to being used in reciprocating pumps, the valves 54, 56 and128 or the components thereof, such as the valve seats 76, 129 and 160,may be used in other types of pumps and fluid systems. Correspondingly,instead of, or in addition to being used in reciprocating pumps, thefluid cylinder 18 or features thereof may be used in other types ofpumps and fluid systems.

In the foregoing description of certain embodiments, specificterminology has been resorted to for the sake of clarity. However, thedisclosure is not intended to be limited to the specific terms soselected, and it is to be understood that each specific term includesother technical equivalents which operate in a similar manner toaccomplish a similar technical purpose. Terms such as “left” and right”,“front” and “rear”, “above” and “below” and the like are used as wordsof convenience to provide reference points and are not to be construedas limiting terms.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise”, “comprised” and “comprises” where they appear.

In addition, the foregoing describes only some embodiments of theinvention(s), and alterations, modifications, additions and/or changescan be made thereto without departing from the scope and spirit of thedisclosed embodiments, the embodiments being illustrative and notrestrictive.

Furthermore, invention(s) have described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention(s). Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. Further, each independent feature orcomponent of any given assembly may constitute an additional embodiment.

What is claimed is:
 1. A pump assembly, comprising: a fluid cylinderhaving a first axis, the fluid cylinder comprising a first fluid passagethrough which fluid is adapted to flow along the first axis, the firstfluid passage defining a first tapered internal shoulder of the fluidcylinder, the first tapered internal shoulder defining a first anglefrom the first axis; and a first valve to control flow of fluid throughthe first fluid passage, the first valve comprising a first valve seatdisposed in the first fluid passage, the first valve seat having asecond axis that is aligned with the first axis, the first valve seatcomprising a first tapered external shoulder, the first tapered externalshoulder defining a second angle from the second axis; wherein each ofthe first and second angles ranges from about 10 degrees to about 45degrees measured from the first axis and the second axis alignedtherewith.
 2. The pump assembly of claim 1, wherein the first taperedinternal shoulder and the first tapered external shoulder define firstand second frusto-conical surfaces, respectively; and wherein the firsttapered internal shoulder engages the first tapered external shoulder todistribute and transfer loading between the first and secondfrusto-conical surfaces.
 3. The pump assembly of claim 1, wherein thefirst and second angles are equal.
 4. The pump assembly of claim 3,wherein each of the first and second angles is about 30 degrees measuredfrom the first axis and the second axis aligned therewith.
 5. The pumpassembly of claim 1, wherein the fluid cylinder further comprises: apressure chamber in fluid communication with the first fluid passage; asecond fluid passage in fluid communication with the pressure chamberand through which fluid is adapted to flow along the first axis, thesecond fluid passage defining a second tapered internal shoulder of thefluid cylinder, the second tapered internal shoulder defining a thirdangle from the first axis; a fluid inlet passage in fluid communicationwith the pressure chamber via the first fluid passage; and a fluidoutlet passage in fluid communication with the pressure chamber via thesecond fluid passage; wherein the pump assembly further comprises asecond valve to control flow of the fluid through the second fluidpassage, the second valve comprising a second valve seat disposed in thesecond fluid passage, the second valve seat having a third axis that isaligned with each of the first and second axes, the second valve seatcomprising a second tapered external shoulder, the second taperedexternal shoulder defining a fourth angle from the third axis; andwherein each of the third and fourth angles ranges from about 10 degreesto about 45 degrees measured from the first axis and each of the secondand third axes aligned therewith.
 6. The pump assembly of claim 5,wherein the second tapered internal shoulder and the second taperedexternal shoulder defines third and fourth frusto-conical surfaces,respectively; and wherein the second tapered internal shoulder engagesthe second tapered external shoulder to distribute and transfer loadingbetween the third and fourth frusto-conical surfaces.
 7. The pumpassembly of claim 5, wherein the third and fourth angles are equal. 8.The pump assembly of claim 7, wherein each of the third and fourthangles is about 30 degrees measured from the first axis and each of thesecond and third axes aligned therewith.
 9. The pump assembly of claim1, wherein the first valve seat further comprises: a seat body, the seatbody comprising an enlarged-diameter portion at one end thereof, theenlarged-diameter portion comprising the first tapered external shoulderand defining a first cylindrical surface extending axially from thefirst frusto-conical surface, the first cylindrical surface defining afirst outside diameter; a bore formed through the seat body, the boredefining a second cylindrical surface, the second cylindrical surfacedefining a first inside diameter; wherein the first fluid passagecomprises an enlarged-diameter portion and a reduced-diameter portionextending axially therefrom; wherein the enlarged-diameter portion ofthe first fluid passage defines the first tapered internal shoulder ofthe fluid cylinder; wherein the reduced-diameter portion of the firstfluid passage defines an inside surface of the fluid cylinder and asecond inside diameter; wherein the enlarged-diameter portion of theseat body is disposed in the enlarged-diameter portion of the firstfluid passage; wherein the seat body defines an outside surface that isengaged with the inside surface of the fluid cylinder; and wherein theoutside surface defines a second outside diameter.
 10. The pump assemblyof claim 9, wherein at least one of the inside surface of the fluidcylinder and the outside surface of the seat body is tapered at a taperangle from the first axis and the second axis aligned therewith, thetaper angle ranging from greater than 0 degrees to about 5 degreesmeasured from the first axis and the second axis aligned therewith. 11.The pump assembly of claim 9, wherein the first valve seat furthercomprises: an annular groove formed in the outside surface of the seatbody, the annular groove defining a groove diameter; and a sealingelement disposed in the annular groove and sealingly engaging the insidesurface of the fluid cylinder.
 12. The pump assembly of claim 11,wherein each of the first and second angles is about 30 degrees; whereinthe first outside diameter is about 5 inches; wherein the first insidediameter is about 3 inches; wherein the second inside diameter is about4.5 inches; wherein the groove diameter is about 4 inches; and whereinthe second outside diameter is about 4.5 inches.
 13. The pump assemblyof claim 1, wherein the fluid cylinder further comprises a pressurechamber in fluid communication with the first fluid passage; and whereinthe pump assembly further comprises a housing connected to the fluidcylinder, and a plunger rod assembly extending out of the housing andinto the pressure chamber.
 14. A fluid cylinder for a pump assembly, thefluid cylinder having a fluid passage axis and comprising: a first fluidpassage through which fluid is adapted to flow along the fluid passageaxis, the first fluid passage defining a first tapered internal shoulderof the fluid cylinder, the first tapered internal shoulder defining afirst angle from the fluid passage axis, the first angle ranging fromabout 10 degrees to about 45 degrees measured from the fluid passageaxis; and a pressure chamber in fluid communication with the first fluidpassage.
 15. The fluid cylinder of claim 14, wherein the first angle isabout 30 degrees measured from the fluid passage axis.
 16. The fluidcylinder of claim 14, further comprising: a second fluid passage influid communication with the pressure chamber and through which fluid isadapted to flow along the fluid passage axis, the second fluid passagedefining a second tapered internal shoulder of the fluid cylinder, thesecond tapered internal shoulder defining a second angle from the fluidpassage axis; and a fluid outlet passage in fluid communication with thepressure chamber via the second fluid passage; wherein the second angleranges from about 10 degrees to about 45 degrees measured from the fluidpassage axis.
 17. The fluid cylinder of claim 16, wherein the first andsecond angles are equal.
 18. The fluid cylinder of claim 17, whereineach of the first and second angles is about 30 degrees measured fromthe fluid passage axis.
 19. The fluid cylinder of claim 14, wherein thefirst fluid passage comprises an enlarged-diameter portion and areduced-diameter portion extending axially therefrom; wherein theenlarged-diameter portion of the first fluid passage defines the firsttapered internal shoulder of the fluid cylinder; and wherein thereduced-diameter portion of the first fluid passage defines an insidesurface of the fluid cylinder and an inside diameter.
 20. The fluidcylinder of claim 19, wherein the inside surface is tapered at a taperangle from the fluid passage axis, the taper angle ranging from greaterthan 0 degrees to about 5 degrees measured from the fluid passage axis.21. The fluid cylinder of claim 19, wherein each of the first and secondangles is about 30 degrees; and wherein the inside diameter is about 4.5inches.
 22. A valve seat adapted to be disposed within a fluid cylinderfor a pump assembly, the valve seat having a valve seat axis andcomprising: a seat body, the seat body comprising an enlarged-diameterportion at one end thereof, the enlarged-diameter portion comprising afirst tapered external shoulder, the first tapered external shoulderdefining a first angle from the valve seat axis, and a frusto-conicalsurface extending at the first angle from the valve seat axis, the firstangle ranging from about 10 degrees to about 45 degrees measured fromthe valve seat axis, wherein the enlarged-diameter portion defines afirst cylindrical surface extending axially from the frusto-conicalsurface, the first cylindrical surface defining a first outsidediameter, wherein the seat body defines an outside surface, the outsidesurface defining a second outside diameter that is less than the firstoutside diameter, and wherein the frusto-conical surface is axiallydisposed between the outside surface and the first cylindrical surface;and a bore formed through the seat body and through which fluid flowsalong the valve seat axis, the bore defining a second cylindricalsurface, the second cylindrical surface defining an inside diameter thatis less than the second outside diameter.
 23. The valve seat of claim22, wherein the first angle is about 30 degrees measured from the valveseat axis.
 24. The valve seat of claim 22, wherein the outside surfaceof the seat body is tapered at a second angle from the valve seat axis;and wherein the second angle ranges from greater than 0 degrees to about5 degrees measured from the valve seat axis.
 25. The valve seat of claim22, further comprising: an annular groove formed in the outside surfaceof the seat body, the annular groove defining a groove diameter that isless than the second outside diameter and greater than the insidediameter; and a sealing element disposed in the annular groove.
 26. Thevalve seat of claim 25, wherein the first angle is about 30 degreesmeasured from the valve seat axis; wherein the first outside diameter isabout 5 inches; wherein the inside diameter is about 3 inches; whereinthe groove diameter is about 4 inches; and wherein the second outsidediameter is about 4.5 inches.
 27. A valve seat adapted to be disposedwithin a fluid cylinder for a pump assembly, the valve seat having avalve seat axis and comprising: a seat body, the seat body comprising anenlarged-diameter portion at one end thereof, the enlarged-diameterportion comprising a first tapered external shoulder, the first taperedexternal shoulder defining a first angle from the valve seat axis, and afrusto-conical surface extending at the first angle from the valve seataxis, wherein the enlarged-diameter portion defines a first cylindricalsurface extending axially from the frusto-conical surface, the firstcylindrical surface defining a first outside diameter, wherein the seatbody defines an outside surface, the outside surface defining a secondoutside diameter that is less than the first outside diameter, whereinthe outside surface of the seat body is tapered at a second angle fromthe valve seat axis, and wherein the frusto-conical surface is axiallydisposed between the outside surface and the first cylindrical surface;and a bore formed through the seat body and through which fluid flowsalong the valve seat axis, the bore defining a second cylindricalsurface, the second cylindrical surface defining an inside diameter thatis less than the second outside diameter.
 28. The valve seat of claim 27wherein the first angle ranges from about 10 degrees to about 45 degreesmeasured from the valve seat axis; and wherein the second angle rangesfrom greater than 0 degrees to about 5 degrees measured from the valveseat axis.
 29. The valve seat of claim 27, wherein the first angle isabout 30 degrees measured from the valve seat axis; and wherein thesecond angle ranges from greater than 0 degrees to about 5 degreesmeasured from the valve seat axis.
 30. The valve seat of claim 27,further comprising: an annular groove formed in the outside surface ofthe seat body, the annular groove defining a groove diameter that isless than the second outside diameter and greater than the insidediameter; and a sealing element disposed in the annular groove.
 31. Thevalve seat of claim 30, wherein the first angle is about 30 degreesmeasured from the valve seat axis; wherein the second angle ranges fromgreater than 0 degrees to about 5 degrees measured from the valve seataxis; wherein the first outside diameter is about 5 inches; wherein theinside diameter is about 3 inches; wherein the groove diameter is about4 inches; and wherein the second outside diameter is about 4.5 inches.32. A method of producing a first pump assembly based on a second pumpassembly, the first and second pump assemblies comprising first andsecond fluid cylinders, respectively, and first and second valve seats,respectively, the first and second fluid cylinders comprising first andsecond fluid passages formed therein, respectively, in which the firstand second valve seats are adapted to be disposed, respectively, thefirst and second fluid passages defining first and second insidediameters, respectively, the first and second valve seats defining firstand second outside diameters, respectively, the method comprising:producing the first fluid cylinder, comprising sizing the first insidediameter to be less than the second outside diameter so that the secondvalve seat is not permitted to be disposed in the first fluid passage;and producing the first valve seat, comprising sizing the first outsidediameter so that: the first outside diameter is less than the secondinside diameter; and a radial clearance would be defined between thefirst valve seat and an inside surface of the second fluid cylinderdefined by the second fluid passage if the first valve seat were to bedisposed in the second fluid passage.
 33. The method of claim 32,further comprising disposing the first valve seat in the first fluidpassage.
 34. The method of claim 32, wherein producing the first valveseat comprises forming an enlarged-diameter portion, theenlarged-diameter portion comprising a tapered external shoulder, thetapered external shoulder defining a first angle, the enlarged-diameterportion defining a cylindrical surface, the cylindrical surface defininga third outside diameter that is greater than the first outsidediameter; and wherein producing the first fluid cylinder comprisesforming the first fluid passage so that the first fluid passage definesa tapered internal shoulder, the tapered internal shoulder defining asecond angle.
 35. The method of claim 34, wherein producing the firstvalve seat further comprises: forming a bore through the first valveseat, the bore defining a third inside diameter that is less than thefirst outside diameter; forming an annular groove in the first valveseat, the annular groove defining a groove diameter that is less thanthe first outside diameter and greater than the third inside diameter;and disposing a sealing element in the annular groove.
 36. The method ofclaim 35, further comprising disposing the first valve seat in the firstfluid passage of the first cylinder so that: the tapered externalshoulder engages the tapered internal shoulder, and the sealing elementsealingly engages the fluid cylinder.
 37. The method of claim 35,wherein each of the first and second angles is about 30 degrees relativeto an axis; wherein the third outside diameter is about 5 inches;wherein the third inside diameter is about 3 inches; wherein the firstinside diameter is about 4.5 inches; wherein the groove diameter isabout 4 inches; and wherein the first outside diameter is about 4.5inches.